This invention relates to refrigerated display cases, and more particularly to air defrost refrigerated display cases employing reverse air flow defrost.
In recent times, concentrated research efforts to conserve valuable and increasingly expensive energy have resulted in a search for defrost capacity using other than the usual electrical defrost or hot refrigerant gas defrost due to the cost of these latter two. As a result, certain air defrost developments have occurred, one of the most advantageous of which is of Japanese origin and which employs reverse air flow through the recirculatory air passage system for defrost operation. This is set forth in U.S. Patent Application Ser. No. 686,895, filed May 17, 1976 and entitled DEFROSTING IN OPEN SHOW CASE OF COLD-AIR-CIRCULATION TYPE, now U.S. Pat. No. 4,026,121, corresponding to published Japanese Patent Application No. 59,908/1975 filed May 20, 1975.
The present invention employs reverse flow air defrost in a special manner with a unique construction, rendering it particularly suitable for open top chest cases.